Process of producing edible oils from crude cottonseed oil



Feb. 18, 1930. w. KELLEY 1,747,675

4 PROCESS OF PRODUCING EDIBLE OILS FROM CRUDE COTTOSEED OIL l Filed July 19. 192e.

Mig/0m 62 4 6 Condenser 55 /0/@55 are Patented Feb. 18V, 1930 vUNITED sTATss PATENT OFFICE WILLIAM KELLEY, OF LOS ANGELES, CALIFORNIA, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO FILTROL COMPANY OF CALIFORNIA, A CORPORATION OF CALI- FORNIA PROCESS F PRODUCING EIDIBLE OILS FROM CRUDE COTTONSEEI) OIL Application led .Tuly 19,

My invention relates to the preparation of edible products from crude cottonseed oil, `which in its natural state is a dark colored liquid containing impurities which render it unfit for use in foods. The process used 'I so by me is not one of general application and is of little or no value in connection with' the refining of other oils, it being generally recognized that the various Vegetable oils differ radically from each other and-from animal fats'and greases and from petroleum, so that each oil presents special problems of itsoWn. In fact, I have found that when applied to some other oils, my process is substantially inoperative. No attempt Will therefore be made to describe or claim wide ranges of equivalents, the successful operation of the process requiring a close adherence to thel following description.

Many attempts have been made to refine crude cottonseed' oil-but the only process at present in use operates substantially as follows: The crude oil Which contains considerable quantities of free fatty acids andother iinpurities'is first treated with caustic soda to neutralize the acid, the soda and acid coinbining to form foots which are removed from the oil and used as soap stock. The oil itself isthen bleached and deodorized. In practice it is necessary to use quantities of caustic sodafar in excess of those theoretically necessary to lneutralize the acids and considerable quantities of neutral oil are saponified or carried down into the footsl and thus carried over with the soap stock which has a very low commercial value.

It is -aii object of my invention to provide means for treating a crude cottonseed oil insuch a manner as to produce an edible oil of superior color and palatability without the use of caustic and Without the high losses occasioned by the caustic process.

My invention may be carried on by various combinations of well known apparatus, that illustrated in the drawing, which is diagrammatic, being Well adapted for the purpose.

In this drawing 1 is a primary agitator 1926.. Serial No. 123,344.

pump, 8 is a condensate pump. All of these parts may be Jacketed to conserve heat.

The agitator tank 1 consists of a tight tank having an oil inlet pipe 11, a water inlet pipe 12, and a Filtrol inlet pipe 13, all these pipes steam coil 16 is situated inthe lower part of` the agitator tank, this coill being supplied with steam from a point not shown. A valve 17 and a pressure pump 17a are provided in the. pipe 15. A sludge pipe 18 connects into the pipe l5, said pipe 15 having a valve 19.

The Filter 24 may be of any suitable construction capable of separating solids fromy liquids introduced through the pipe 15 under pressure of the pump 17a, the filtered liquid being delivered through a pipe 21 having a valve 22 into the vaporizer 3.

The vaporizer 3 is preferably in the form of a closed tank having an outlet circulating pipev31 provided with a pressure pump 31a for conducting oil from the bottom of the vaporizer tank into the top of the heater 4 and having a pipe 32 through which heated oil is delivered'from the bottom of the heater 4 into the upper portionof the vaporizer 3. The bottom of the vaporizer 3 is provided with an outlet pipe 3 3 having a valve 34. A

' being closed by suitable valves. The agitasteam vcoil 35 is situated inside and near the bottom of the vaporizer 3, this steam coil beingl lperforated with small holes through which steam may be distributed through the body of oil in the vaporizer, the fiow of steam being controlled by a valve 36. Vapor is delivered from the vaporizer 3 to the trap 5 through a pipe 37 Q The heater 4 is preferably in the form of a worm or spiral pipe through which oil circulates from the pipe 31 to the pipe 32. This pipe may be enclosed in any suitableheat directing and conserving structure not shown, and heated by av gas burner 41 or any other suitable means.

The trap-'5 is preferably a closed vessel having the pipe 37 projecting into its lower part. Any liquid carried over with the vapor through the pipe 37 and collecting in the trap an open communication between the manifold spaces 63', the tubes passing through the coolingwater space 62. Coo ing water is passedthrough the cooling water space by means of pipes 64 from any convenient source not shown'. lThe pipe 53 delivers vapors to one of the manifold spaces 63. Condensates collecting in the other manifold space may -be withdrawn bythe condensate pump 8 y through al pipe 66 having .a valve 67. The

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condensates so withdrawn are discharged by thepump 8 through apipe 68 into a separator G9. This separator may be of any desired construction, but in the form shown comprises a gravity-settling tank 70 in which nonmisci le liquids may stratify and be decant'- ed therefrom through 'valved pipes 71 and 72 provided in the tank 70. F1xed gases 'and uncondensed vapors are withdrawn from the space 63 by the vacuumy pump 7 through a pipe 75. l

.lhe' method of operation, which must be closely followed if satisfactory results are to be obtained is as follows:

The valve 17 being closed, the agitator tank 1 is lilled with crude cottonseed oil.l This oil contains many impuritiesl such as colloidal and mucilaginous matter aswell as free fatty acids and other decomposition products. The oil is vthen heated by the .steam coil'16 to about 115 F. and fiveper cent to ten per cent of water is added through the pipe 12.

The mixture is then agitated by the, paddles for about iiveminutes.v This washing and agitation with accurate ,temperature control coagulates'some of the colloidal impurities carried in the oil. When the' coagulation is com lete the a itation is stop ed and the coagu ates are a lowed to sett e, being withdrawn with the water through the pipe 18 by opening the valve 19.l As soon as the lWater and coagulate's have been removed, the valve 19 is closed and the temperature of the oil is raised to about 170 F. and from three per cent to ten per cent of Filtrol or other de# colorizing clay is added. Filtrol is a well 4known and widely used decolorizing clay hav-v ing properties somewhat similar to -fullers i earth, but being of much greater adsorbent efficiency. It is the product of the treatment of hydrosilicate cla with strong sulfuric acid, followed by a t orough washing out of the soluble sulfates so formed. It contains principally silica in porous Iform, some comined aluminum, acid-soluble aluminum and acid-soluble magnesium'.-

The temperature of the oil is now raised to between 212 F. and 220 F. by superheated steam in the coil 16. During this heating the Filtrol is thoroughly mixed with the oil by a tight shell\1/neans'of the paddles 14. I After agitation at this raised temperature for 'a short period oltime, thet entire charge is forced by the pump 17 through the filter 2 and into the 1ii'aporizer 3, through the pipes 15 and 21, the valves 17 and 22 being opened for the purpose.

In the filter 2 the Filtrol and other solids are removed from the oil; It should be noted, v

however, that the oil iiowing from4 the filter 2 into the vaporizer 3 still containsall the free fatty acids contained in the original oil but it has been freed of its colloids due to their coagulation and from its suspended solid and other impurities by its treatment with Filtrol and subsequent filtration.

The valve 34 being already closed, the valves 22 and 52 are closed and a vacuum is established by the vacuum pump 7 pulling gas and vapor through the condenser 6 and trap 5. In practice the pump 7 or otherI well known means is employed to establish avery high vacuum in the top of the vaporizer 3, an absolute pressure of not over'GO millimeters of mercury being desirable and lower absolute lpressures producing superior results. The pump 3'1" of the. heater 4 is then put into action circulating oil from the vaporizcr 3, through thepipe 31 and the heater 4, and back into the vaporizer through the pipe 32.

The temperature of the oil in the vaporizer is During this time the free fatty acids are vaporized andwithdrawn through -the pipe' 37; The free fatty acids vaporize freely it steam, referably heated to a temperature above that of the oil, is introduced through the perforated pipe 35. A relatively small l I Weight of steam is needed since it expands .greatly at the high vacuum used. v The steam acts partlyV as an agitating agent but also Serves to lower the partial vapor pressureon the free fat/ty acids so that they distil 'over at temperatures far below their atmospheric boiling point. Any free drops of liquid carried over in the stream of vapor in the pipe 37 is caught in the trap 5 from which it may be removed through the pipe 51 and valve 52. 'l

The mixture of steam and vapor from the trap '5 is delivered through the pipe 53 into the condenser 6 in which almost all of the steam and vapor is condensed, being pumped out ofthe -condenser by the condensate pump 8,. The condensates so withdrawn consist almost wholly of free fatty acids which are themselves free from impurities and of high quality and which are readily salable at a high price when these have been-isolated by passage through the separator 69.

The vacuum pump 7 withdraws fixed gases and uncondensed/vapors and thus maintains the desired vacuum.

been blown with steam under vacuumas just described, may be lWithdrawn through the "pipe 33 by opening the valve 34 and lis absolan acid-activated adsorbent clay at a temlutely free from any trace of'free fatty acid `and has a sweet and neutral fiavor which renders it extremely valuable as a food product. L I have found that the above sequence of operations must be closely followed if good results are .to be obtained. I find, for example, that it is necessary to coagulate the colloids before treating with Filtrol and absolutely necessary to remove -all solid or colloidal 11npurities before attempting to remove the fatty acids by distillation, if a valuable'commercial product is to' be obtained. I have found further that unless this distillation -is conducted under the vacuum and' in the manner specified the color, odorv or taste of the finished oil are much impaired.v

I c-laim as my invention: v

1-. A process of producing an edible 4oil'L from a crude cottonseed oil which comprises:

vagita'ting the oil with from 5% to 10% ofwaterat a temperature of about 115 F. to coagulate the colloids therein; removing the colloids and water; agitatingthe `o1l-w1th peraturel of between 212 F. and 220 F.; filtering saidl oil to remove the adsorbent agent and other insoluble impurities therefrom; and heating the filtered oil to a'tem perature of about 450 F. under an absolute pressure of millimeters of mercury'or below, in the presence of steam, which further lowers the partial vapor pressure of the oil, for the purpose of distillingv off the free fatty 2. A process -of producing an edible oil from a crude cottonseed oil ywhich, comprises: agitating the oil with from 5% to 10% of water ata temperatureof about 115v F. vto coagulate the colloids therein; removing'the colloids and water; a Vitating the oil f with an acid-*activated adsor ent clay1 at a temperature of between 212 F. and 220 F.;

heated steamffor the flteringsaid oil to remove the -adsorbent 'agent and other-insoluble im urities therefrom; and .heating the filtere oilto a temperature of about 450, F. under an absolute ressure of millimeters of mercu orbe-l ow and introducing! a current o super p purposeof distilling off the free fatty acids.

colloidsand water; agitating the oil :with an acid-activated adsorbent clay ata temperature ofbetween 212 F. and 220 F.; filtering said oilA to removethe adsorbent agent and 'other insoluble impurities therefrom.;

The oil in thevaporizer 3, after havingand heating the'liltered oil to a temperature of 'about 4 450 F. under a. low .absolute pressure, inthe presence of steam. which further i lowers the partial vapor pressure of the oil, fordthe purpose of distilling voil' the free fatty acl s.

4. A process of producin an edible oil from 'a crude cottonseed oil which comprises: agitating the oil with from 5% to 10% ofwater at a tcmper'atureof about 115 F. to coagulate the colloids therein; removing the colloids and water; raising the temperature of the oil to about 170 F.; adding Van acid-activated adsorbent clay v at this temperature; agitating the oil and said adsorbent agent concurrently with raising the` temperature to between 212 F. and 220 F.; filtering said oil to remove 4`the adsorbent agent and other insoluble impurities therefrom; and heating the filtered oil to a ternperature of about 450o F. iunder an absolute pressure of 60 millimetersof mercury or below, in the presence'of-steam, which further lowersI the partial vapor pressure of the oil, fordthe purpose of distlling off the free fatty acl s.

5. A process offproducingan edible oil 'from a crude cottonseed oil which compr1ses: agltating the oil with from 5%4 to` 10% of water at a temperature of about 115 F. to coagulate the colloids therein; removlng the colloids 'and,water; raising the temperature of the oil to about 170 14.; adding an acid-activated adsorbent clay at this temperature; -agitating the oil and -said ad sorbent agent concurrently with raising the temperature to between 212 F.` and 220" F.;

filtering said oil to remove the adsorbent v agent and other insoluble impurities therefrom; and heating the filtered o il to a temperature of about 450 F. under a low absolutepressure, in the presence of steam, which further lowers the partial vapor pressure of the oil,1J for the purpose of distilling ofi' the free fatty acids.k f

In testimony whereof, I have hereunto set my hand at Los Angeles, California, this 12th day of J uly,`

'V WILLIAM KELLEY.

f 3. A process of produca an edible oil I from a crude cottonse'ed oil w ich comprises: 

